code: def cross_product(v1, v2, v3):
      """Returns the cross-product of vectors (v2 - v1) and (v3 - v1)
      That is : (v2 - v1) X (v3 - v1)
      """
      v2 = [v2[j] - v1[j] for j in range(0, 3)]
      v3 = [v3[j] - v1[j] for j in range(0, 3)]
      return [
          v3[2] * v2[1] - v3[1] * v2[2],
          v3[0] * v2[2] - v3[2] * v2[0],
          v3[1] * v2[0] - v3[0] * v2[1],
      ]
  
imports: from functools import cmp_to_key
  from sympy.abc import x, y, z
  from sympy.core import S, diff, Expr, Symbol
  from sympy.core.sympify import _sympify
  from sympy.geometry import Segment2D, Polygon, Point, Point2D
  from sympy.polys.polytools import LC, gcd_list, degree_list, Poly
  from sympy.simplify.simplify import nsimplify
label_desc: Use image node_id 15 for calling a global function with example usage: cross_product(v1, v2, v3) and returns: list